This invention relates to compositions and processes for applying artificial extensions to natural fingernails and/or for applying protective coatings to natural fingernails or toenails. More particularly, this invention relates to improved processes for attaching such artificial nail structures and coating natural nail surfaces which advantageously provides a smooth, durable coated surface upon which a conventional nail polish can be applied.
A wide array of artificial nail structures are available for attachment to natural nails (see, for example, U.S. Pat. No. 4,407,310 to Jadow, Oct. 4, 1983). Each of these structures has its own individual strengths and weaknesses, however two broad groups of artificial nails are observed to exist. In the first, the artificial nail structure covers substantially the entire surface of the natural nail to which it is attached. These type of structures suffer from the extreme drawback of preventing air from permeating into the natural nail bed, and thus require frequent removal (generally every 24-48 hours) to prevent damage to the natural nails. Additionally, such nails can serve as breeding stimulants for fungus infections, and, thus, the underlying nail bed must be kept scrupulously clean. Further, due to this lack of the natural nail "breathing" the user of such nail extensions may experience loss of normal touch sensation, and the ends of the nails may feel dead.
The second type of artificial nail consists of preformed nails which are applied to the outwardly extending edge of the natural nail, edge-to-edge with a slight overlap by means of various adhesives. When such nails are used, the application of the nail requires a substantial amount of manual dexterity, and additionally, the entire surface of both the natural and artificial nails must be coated with a substance which will "blend in", both nails and specifically avoid any appearance of a boundary joint between the two. Only after this boundary is smoothed, will the artificial extension appear as part of the natural nail.
A wide variety of techniques have been used to seal this joint. For example, in nail sculpting the clean nail is coated with a glue, usually a cyanoacrylate material which binds the artificial nail to the natural one. Then, a small brush is wetted with a liquid consisting of a blend of mono, di and trimethacrylate esters and a promoter, usually N,N-dimethyl-para-toluidine which is capable of inducing decomposition of benzoul peroxide at room temperature. The wetted brush is then dipped into a finely powdered polymethacrylate ester to form a dough which begins to cure immediately. The dough is quickly placed unto the prepared nails and smoothed or sculptured in place to cover the joint. More dough is added until the nail is covered and filled to the desired uniform thickness and shape. Filing, buffing and sometimes the addition of more dough result in a strong and durable surface to which polish can be applied. However, this system suffers from the drawback of requiring a wide array of materials, in addition to the cyanoacrylate adhesive which is originally used to bond the artificial nail to the natural nail, for proper use.
The use of cyanoacrylate itself as a filler has also been accomplished. In such a procedure the artificial nail is originally glued on to the tip of the natural nail by use of a cyanoacrylate glue. Once strong bonding is effected, the entire surface of the artificial and natural nail is coated with a viscous cyanoacrylate adhesive. This is accomplished in a three step process. Initially, the adhesive is applied to the nail surface. Subsequently, the adhesive is evenly spread across the surface by a solvent which is capable of dissolving the cyanoacrylate and is also readily evaporated at room temperature, to leave behind a smooth, even layer of cyanoacrylate. Finally, this layer is then cured by the application of an initiator, such as the dimethyl-para-toluidine, in a spray. This results in a hard, polymer-coated nail which can be polished; the joint is completely covered and hidden.
However, this procedure suffers from the drawback that the polymerization of the cyanoacrylate can be quite exothermic, and depending on the amount of promoter applied, quite high temperatures can be realized on the surface of the nail; these temperatures can cause great discomfort to the user. Additionally, the solvents normally used in spray applications, 1,1,1,-trichloroethylene, freons, and/or mixtures thereof, can cause potential problems when used in cosmetological applications since they may be potentially health hazards.
Thus, there exists a real need for a method of artificial nail application which will overcome these drawbacks. Such a procedure will provide for easy attachment and coating of said nails to achieve a natural and attractive appearance, not require great dexterity to attach the nails, and avoid the use of potentially hazardous solvents.
The same problems are observed when these fillers are used as protective coatings for natural fingernails or toenails (without the artificial extension). While it is desirable to achieve a tough, smooth, and resilient coating on the nail surface, these drawbacks limit the utility of the fillers in this regard. Thus, there exists a real need for a method for coating natural nails which overcomes these drawbacks.